274 PSYCHIATRY 



and is reaching conclusions that may yet illuminate some of^the dark 

 places of psychiatry. The history of morphology has a special signi- 

 ficance in its development cotemporary with other biological sciences; 

 the changes in its course suggest a law of progress in scientific re- 

 search that has operated in other fields. After the emergence of mor- 

 phology, and of physiology, from the keeping 9f anatomy, the two 

 new sciences entered upon equal domains in the realm of biology. 

 Morphology asserted the independence of the science of form and 

 structure from that of function ; the doctrine was that form persists 

 and function varies. It was characterized by the conception of a 

 fixity of types, a rigid adherence to the study of mature forms which 

 it labored to arrange in a perfected and systematic classification. 

 With the breaking-away from these rigid conceptions, during the last 

 fifty years, the course of progress was in the study of the problems of 

 evolution; leading through the investigations concerning the origin 

 of species, it has come to the recognition of the supreme importance 

 of the problems involved in the development of the individual, and of 

 the biological laws that govern it ; and the wide range of variations 

 that may be produced in members of a given species. So in medi- 

 cine, instead of clinical types, the differentiations of disease are 

 becoming genetic and developmental in character. 



In the morphology of plant and animal life it is agreed on both 

 sides that they are subject to the same laws; in both plants and 

 animals there are identical processes which are consistent with the 

 significance of the cell doctrine as being fundamental to morphology. 

 In the close relation of form and function the modern conception is 

 that the structural characters of which, an individual organism is 

 made up correspond to its functional characters; form characteris- 

 tics cannot be understood without considering the function charac- 

 teristics. Physiological characteristics are transmissible in the same 

 way as the morphological. The study of physiological cytology and 

 embryology is revealing the mechanism of the transmission of quali- 

 ties; with the aid of the experimental methods in the production of 

 variations in both form and function, there is great progress in the 

 understanding of the laws of descent and inheritance. The close 

 relation of physiological and morphological characteristics proves 

 that the problems of form and structure are also physiological prob- 

 lems. Physiological processes are influenced and often controlled by 

 the conditions of the environment both internal and external ; and it 

 is shown that mental as well as physiological characteristics are 

 inherited under the same laws. These brief references to the data of 

 morphology serve here to indicate the trend of progress in this science; 

 it points to the conclusion that influences which stimulate functional 

 activity play an essential part in determining the processes of 

 development and the resulting structural forms. The demonstrations 



